Monocular telescope having a focusing unit whose mechanical sensitivity can be varied

Abstract

A monocular telescope having a constant length includes a lens mounted in a tube and interchangeable eyepieces to vary the magnification. Focusing is performed using a positioning member to move a focusing unit axially in the tube. The rate of focus adjustment is adaptable to the selected magnification due to the provision of a transmission gear having different diameter gear wheels arranged along the positioning member. The transmission gear can be operatively coupled to the interchangeable eyepiece.

What is claimed is: 
     
       1. A monocular telescope having a constant length, comprising: a lens arranged in a tube, the tube accommodating interchangeable eyepieces which vary the magnification of the telescope;   a focusing unit which moves by adjusting a positioning member; and   a transmission gear assembly, coupled to the focusing unit and to the positioning member, which sets the rate at which the focusing unit moves for focusing per unit of rotation of the positioning member to one of at least two different rates.   
     
     
       2. A monocular telescope as claimed in claim 1, wherein the positioning member includes a shaft and wherein the transmission gear assembly includes at least two differently sized gears along the shaft. 
     
     
       3. A monocular telescope as claimed in claim 1, wherein the positioning member is operatively coupled by a mechanical assembly to an interchangeable eyepiece such that the interchangeable eyepiece determines the position of the positioning member. 
     
     
       4. A monocular telescope as claimed in claim 1, wherein the focusing unit includes a lens system. 
     
     
       5. A monocular telescope as claimed in claim 1, wherein the focusing unit includes a prism system. 
     
     
       6. A monocular telescope as claimed in claim 3, wherein the mechanical assembly includes a control pin which is displaceable with a collar on the interchangeable eyepiece and which is coupled to an angle lever which acts on the positioning member. 
     
     
       7. A telescope, comprising: a tube, the tube accommodating one of a set of interchangeable eyepieces which determine the magnification of the telescope, the length of the tube and any of the interchangeable eyepieces being constant;   a focus control actuator;   focusing optics;   a carriage to control movement of the focusing optics, the carriage having at least two toothed racks;   a transmission gear assembly having at least two differently sized gears; and   an assembly, coupled to the focus control actuator and to the carriage, which selectively causes one of the at least two differently sized gears to engage one of the at least two toothed racks such that the rate at which the focusing optics move for focusing is set in accordance with a chosen magnification.   
     
     
       8. A monocular telescope having a constant length, comprising: a lens arranged in a tube, the tube accommodating interchangeable eyepieces which vary the magnification of the telescope;   a focusing unit which moves by adjusting a positioning member; and   a transmission gear assembly, coupled to the positioning member, for moving the focusing unit at two or more different rates.   
     
     
       9. A monocular telescope as claimed in claim 8, wherein said transmission gear assembly comprises at least two differently sized gears. 
     
     
       10. A monocular telescope having a constant length, comprising: a lens arranged in a tube, the tube accommodating interchangeable eyepieces which vary the magnification of the telescope;   a focusing unit which moves by adjusting a positioning member; and   a transmission gear assembly, coupled to the positioning member, which provides coarse and fine adjustment for the focusing unit.